/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.engine.impl.persistence.entity;

import java.util.Arrays;
import java.util.Date;
import java.util.List;

import org.activiti.engine.delegate.VariableScope;
import org.activiti.engine.delegate.event.ActivitiEventType;
import org.activiti.engine.delegate.event.impl.ActivitiEventBuilder;
import org.activiti.engine.impl.Page;
import org.activiti.engine.impl.TimerJobQueryImpl;
import org.activiti.engine.impl.calendar.BusinessCalendar;
import org.activiti.engine.impl.calendar.CycleBusinessCalendar;
import org.activiti.engine.impl.cfg.ProcessEngineConfigurationImpl;
import org.activiti.engine.impl.context.Context;
import org.activiti.engine.impl.jobexecutor.TimerEventHandler;
import org.activiti.engine.impl.persistence.CountingExecutionEntity;
import org.activiti.engine.impl.persistence.entity.data.TimerJobDataManager;
import org.activiti.engine.runtime.Job;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author Tijs Rademakers
 */
public class TimerJobEntityManagerImpl extends AbstractEntityManager<TimerJobEntity> implements TimerJobEntityManager {

  private static final Logger logger = LoggerFactory.getLogger(TimerJobEntityManagerImpl.class);

  protected TimerJobDataManager jobDataManager;
  
  public TimerJobEntityManagerImpl(ProcessEngineConfigurationImpl processEngineConfiguration, TimerJobDataManager jobDataManager) {
    super(processEngineConfiguration);
    this.jobDataManager = jobDataManager;
  }
  
  @Override
  public TimerJobEntity createAndCalculateNextTimer(JobEntity timerEntity, VariableScope variableScope) {
    int repeatValue = calculateRepeatValue(timerEntity);
    if (repeatValue != 0) {
      if (repeatValue > 0) {
        setNewRepeat(timerEntity, repeatValue);
      }
      Date newTimer = calculateNextTimer(timerEntity, variableScope);
      if (newTimer != null && isValidTime(timerEntity, newTimer, variableScope)) {
        TimerJobEntity te = createTimer(timerEntity);
        te.setDuedate(newTimer);
        return te;
      }
    }
    return null;
  }

  @Override
  public List<TimerJobEntity> findTimerJobsToExecute(Page page) {
    return jobDataManager.findTimerJobsToExecute(page);
  }

  @Override
  public List<TimerJobEntity> findJobsByTypeAndProcessDefinitionId(String jobHandlerType, String processDefinitionId) {
    return jobDataManager.findJobsByTypeAndProcessDefinitionId(jobHandlerType, processDefinitionId);
  }
  
  @Override
  public List<TimerJobEntity> findJobsByTypeAndProcessDefinitionKeyNoTenantId(String jobHandlerType, String processDefinitionKey) {
    return jobDataManager.findJobsByTypeAndProcessDefinitionKeyNoTenantId(jobHandlerType, processDefinitionKey);
  }
  
  @Override
  public List<TimerJobEntity> findJobsByTypeAndProcessDefinitionKeyAndTenantId(String jobHandlerType, String processDefinitionKey, String tenantId) {
    return jobDataManager.findJobsByTypeAndProcessDefinitionKeyAndTenantId(jobHandlerType, processDefinitionKey, tenantId);
  }
  
  @Override
  public List<TimerJobEntity> findJobsByExecutionId(String id) {
    return jobDataManager.findJobsByExecutionId(id);
  }
  
  @Override
  public List<TimerJobEntity> findJobsByProcessInstanceId(String id) {
    return jobDataManager.findJobsByProcessInstanceId(id);
  }
  
  @Override
  public List<Job> findJobsByQueryCriteria(TimerJobQueryImpl jobQuery, Page page) {
    return jobDataManager.findJobsByQueryCriteria(jobQuery, page);
  }
  
  @Override
  public long findJobCountByQueryCriteria(TimerJobQueryImpl jobQuery) {
    return jobDataManager.findJobCountByQueryCriteria(jobQuery);
  }
  
  @Override
  public void updateJobTenantIdForDeployment(String deploymentId, String newTenantId) {
    jobDataManager.updateJobTenantIdForDeployment(deploymentId, newTenantId);
  }
  
  @Override
  public boolean insertTimerJobEntity(TimerJobEntity timerJobEntity) {
    return doInsert(timerJobEntity, true);
  }
  
  @Override
  public void insert(TimerJobEntity jobEntity) {
    insert(jobEntity, true);
  }
  
  @Override
  public void insert(TimerJobEntity jobEntity, boolean fireCreateEvent) {
    doInsert(jobEntity, fireCreateEvent);
  }

  protected boolean doInsert(TimerJobEntity jobEntity, boolean fireCreateEvent) {
    // add link to execution
    if (jobEntity.getExecutionId() != null) {
      ExecutionEntity execution = getExecutionEntityManager().findById(jobEntity.getExecutionId());
      if (execution != null) {
        execution.getTimerJobs().add(jobEntity);
  
        // Inherit tenant if (if applicable)
        if (execution.getTenantId() != null) {
          jobEntity.setTenantId(execution.getTenantId());
        }
        
        if (isExecutionRelatedEntityCountEnabled(execution)) {
          CountingExecutionEntity countingExecutionEntity = (CountingExecutionEntity) execution;
          countingExecutionEntity.setTimerJobCount(countingExecutionEntity.getTimerJobCount() + 1);
        }
        
      } else {
        // In case the job has an executionId, but the Execution is not found,
        // it means that for example for a boundary timer event on a user task,
        // the task has been completed and the Execution and job have been removed.
        return false;
      }
    }

    super.insert(jobEntity, fireCreateEvent);
    return true;
  }

  @Override
  public void delete(TimerJobEntity jobEntity) {
    super.delete(jobEntity);

    deleteExceptionByteArrayRef(jobEntity);
    removeExecutionLink(jobEntity);
    
    if (jobEntity.getExecutionId() != null && isExecutionRelatedEntityCountEnabledGlobally()) {
      CountingExecutionEntity executionEntity = (CountingExecutionEntity) getExecutionEntityManager().findById(jobEntity.getExecutionId());
      if (isExecutionRelatedEntityCountEnabled(executionEntity)) {
        executionEntity.setTimerJobCount(executionEntity.getTimerJobCount() - 1);
      }
    }
    
    // Send event
    if (getEventDispatcher().isEnabled()) {
      getEventDispatcher().dispatchEvent(ActivitiEventBuilder.createEntityEvent(ActivitiEventType.ENTITY_DELETED, this));
    }
  }
  
  /**
   * Removes the job's execution's reference to this job, if the job has an associated execution.
   * Subclasses may override to provide custom implementations.
   */
  protected void removeExecutionLink(TimerJobEntity jobEntity) {
    if (jobEntity.getExecutionId() != null) {
      ExecutionEntity execution = getExecutionEntityManager().findById(jobEntity.getExecutionId());
      if (execution != null) {
        execution.getTimerJobs().remove(jobEntity);
      }
    }
  }

  /**
   * Deletes a the byte array used to store the exception information.  Subclasses may override
   * to provide custom implementations. 
   */
  protected void deleteExceptionByteArrayRef(TimerJobEntity jobEntity) {
    ByteArrayRef exceptionByteArrayRef = jobEntity.getExceptionByteArrayRef();
    if (exceptionByteArrayRef != null) {
      exceptionByteArrayRef.delete();
    }
  }
  
  protected TimerJobEntity createTimer(JobEntity te) {
    TimerJobEntity newTimerEntity = create();
    newTimerEntity.setJobHandlerConfiguration(te.getJobHandlerConfiguration());
    newTimerEntity.setJobHandlerType(te.getJobHandlerType());
    newTimerEntity.setExclusive(te.isExclusive());
    newTimerEntity.setRepeat(te.getRepeat());
    newTimerEntity.setRetries(te.getRetries());
    newTimerEntity.setEndDate(te.getEndDate());
    newTimerEntity.setExecutionId(te.getExecutionId());
    newTimerEntity.setProcessInstanceId(te.getProcessInstanceId());
    newTimerEntity.setProcessDefinitionId(te.getProcessDefinitionId());

    // Inherit tenant
    newTimerEntity.setTenantId(te.getTenantId());
    newTimerEntity.setJobType(JobEntity.JOB_TYPE_TIMER);
    return newTimerEntity;
  }

  protected void setNewRepeat(JobEntity timerEntity, int newRepeatValue) {
    List<String> expression = Arrays.asList(timerEntity.getRepeat().split("/"));
    expression = expression.subList(1, expression.size());
    StringBuilder repeatBuilder = new StringBuilder("R");
    repeatBuilder.append(newRepeatValue);
    for (String value : expression) {
      repeatBuilder.append("/");
      repeatBuilder.append(value);
    }
    timerEntity.setRepeat(repeatBuilder.toString());
  }
  
  protected boolean isValidTime(JobEntity timerEntity, Date newTimerDate, VariableScope variableScope) {
    BusinessCalendar businessCalendar = getProcessEngineConfiguration().getBusinessCalendarManager().getBusinessCalendar(
        getBusinessCalendarName(TimerEventHandler.geCalendarNameFromConfiguration(timerEntity.getJobHandlerConfiguration()), variableScope));
    return businessCalendar.validateDuedate(timerEntity.getRepeat(), timerEntity.getMaxIterations(), timerEntity.getEndDate(), newTimerDate);
  }
  
  protected Date calculateNextTimer(JobEntity timerEntity, VariableScope variableScope) {
    BusinessCalendar businessCalendar = getProcessEngineConfiguration().getBusinessCalendarManager().getBusinessCalendar(
        getBusinessCalendarName(TimerEventHandler.geCalendarNameFromConfiguration(timerEntity.getJobHandlerConfiguration()), variableScope));
    return businessCalendar.resolveDuedate(timerEntity.getRepeat(), timerEntity.getMaxIterations());
  }
  
  protected int calculateRepeatValue(JobEntity timerEntity) {
    int times = -1;
    List<String> expression = Arrays.asList(timerEntity.getRepeat().split("/"));
    if (expression.size() > 1 && expression.get(0).startsWith("R") && expression.get(0).length() > 1) {
      times = Integer.parseInt(expression.get(0).substring(1));
      if (times > 0) {
        times--;
      }
    }
    return times;
  }
  
  protected String getBusinessCalendarName(String calendarName, VariableScope variableScope) {
    String businessCalendarName = CycleBusinessCalendar.NAME;
    if (StringUtils.isNotEmpty(calendarName)) {
      businessCalendarName = (String) Context.getProcessEngineConfiguration().getExpressionManager()
          .createExpression(calendarName).getValue(variableScope);
    }
    return businessCalendarName;
  }
  
  protected TimerJobDataManager getDataManager() {
    return jobDataManager;
  }

  public void setJobDataManager(TimerJobDataManager jobDataManager) {
    this.jobDataManager = jobDataManager;
  }
}
